Name
Period
Date
Pre-AP Chemistry
Worksheet: Mole Calculations & Percent Composition
A. Mole Calculations. You will need a periodic table to look up molecular weights. Do each type of calculation until you feel
that you could do it without looking at notes. If you are very comfortable with a problem, skip down to harder ones. The
answers will be on the web.
1.
________________How many moles of Na are in 42 g of Na?
2.
________________How many moles of O are in 8.25 g of O?
3.
________________How much does 2.18 mol of Cu weigh?
4.
________________What is the mass of 0.28 mol of iron?
5.
________________How many atoms are in 7.2 mol of chlorine?
6.
________________How many atoms are in 36 g of bromine?
7.
________________How many moles are in 1.0 x 109 atoms?
8.
________________What is the mass of 1.20 x 1025 atoms of sulfur?
9.
________________How many moles of CO molecules are in 52 g of CO?
10.
________________How many moles of C2H6 are in 124 g?
11.
________________How many moles of CCl4 are there in 56 g?
12.
________________How much does 2.50 mol of H2SO4 weigh?
13.
________________How much does 0.25 mol of Fe2O3 weigh?
14.
________________How many molecules are there in 52 g of CO?
15.
________________How many formula units are in 22.4 g SnO2?
16.
________________How many molecules are in 116 g CCl4?
17.
________________What is the mass of 3.01 x 1023 formula units of Fe2O3?
18.
________________What is the mass of 1.2 x 1025 molecules of CO?
19.
________________How many O atoms are in 1.25 mol of SO2?
20.
________________How many moles of O atoms do you have when you have 1.20 x 1025 N2O5 molecules?
21.
________________How many formula units are in 5.33 mol of CuCl2?
22.
________________How many copper atoms are in 5.33 mol of CuCl2?
23.
________________How many moles of Cl atoms are in 5.33 mol of CuCl2?
Worksheet: Mole Calculations
1
11/19/14
Calculate the percent composition of the compounds that are formed from these reactions:
1. 9.03 g of Magnesium combine completely with 3.48 g of Nitrogen.
2. 29.0 g of Argon combine completely with 4.30 g of Sulfur.
3. 222.6 g of Sodium combine completely with 77.4 g of Oxygen.
Calculate the percent composition of each of the following compounds:
4. C2H6
5. NaHSO4
6. Ca(C2H3O2)2
7. HCN
8. H2O
Calculate the mass of the element in the given mass of compound:
9. Mass of Hydrogen in 350 g C2H6
10. Mass of Oxygen in 20.2 g of NaHSO4
11. Mass of Hydrogen in 124 g of Ca(C2H3O2)2
12. Mass of Nitrogen in 378 g HCN
Worksheet: Mole Calculations
2
11/19/14
Answers
1. 1.8 mol Na
2. 0.516 mol O
3. 139 g Cu
4. 16 g Fe
5. 4.3 x 1024 Cl atoms
6. 2.7 x 1023 Br atoms
7. 1.7 x 10-15 mol
8. 639 g S
9. 1.9 mol
10. 4.12 mol
11. 0.36 mol
12. 245 g
13. 39.9 g
14. 1.1 x 1024 molecules
15. 8.95 x 1022 formula units
16. 4.54 x 1023 molecules
17. 79.9 g Fe2O3
18. 5.6 x 102 g CO
19. 1.51 x 1024 O atoms
20. 99.7 mol O
21. 3.21 x 1024 formula units
22. 3.21 x 1024 Cu atoms
23. 10.7 mol of Cl atoms
24. 0.10 mol CuCl2
25. 3.79 x 1024 O atoms
26. 6.79 x 1023 H atoms
Worksheet: Mole Calculations
3
11/19/14
Worksheet: Mole Calculations
4
11/19/14